Ok, here is the video.
First the Prince 48x50 (tip speed 915fps)
Second the Cloudcars 52x60 (tip speed 998fps, likely transsonic)
Third the Cloudcars 52.5x56 (tip speed 824fps)
All of these passes are around the mid 190's. Its hard to tell the difference between the exhaust noise and prop noise at first. Listen to how much louder the second prop is.
The Prince and the 52x60 are louder. The last prop is much quieter and the exhaust noise is very distinct. I am not offering definitive answers as to why, but here is a difference between the three.